In designing and testing hardware interface logic for devices to be used with conventional bus computers, a primary task is to design hardware logic which will accomplish assigned tasks with optimal efficiency and as many desirable features as possible. For example, a video interface card intended for insertion into an industry standard Peripheral Component Interconnect ("PCI") bus computer would, ideally, quickly draw and refresh images on a video screen, with a maximum number of colors and other desirable features available. However, no matter how well designed such an interface is, it is of no value unless it communicates well with the computer's processor and other devices, as necessary, by means of the computer bus. Therefore, the makers of such hardware interfaces must give close attention to the design and testing of the interfaces for proper communication with the computer bus.
Several companies currently provide logic simulators, which are software tools which provide a means by which logic designers can emulate a working environment for hardware devices, such as the video interface card discussed above, so that the new hardware devices can be tested for proper operation in relation to the bus interface. Some of these vendors, as well as some other independent developers, provide "models" which plug into the software simulators. The models provide the necessary traffic on the bus to test new hardware interface devices. Such models are commonly written in one or both of two languages which are readily available and well known in the field: "VHDLtm" (VERY HIGH SPEED INTEGRATED CIRCUIT HARDWARE DESCRIPTION LANGUAGE) or "Verilogtm". Such models generally include a set of instructions for sending and receiving data to and from the device under test such as could be expected in a "real" application of the device, and further for storing the results of the data interchanges so that the results can be retrieved and studied at the end of the test.
Existing prior art models have performed quite effectively where there are few, or relatively few problems encountered during a test. However, as devices get even more complex, it becomes more important that models might, somehow, be able to become more interactive such that they are more of an aid in troubleshooting a complex interface problem rather than just a reporter of such problem. To the inventor's knowledge, prior to the present invention, no means has existed in the art for providing such dynamic interaction between the model, the simulator, and the device under test. All prior methods and means have generally just run preprogrammed tests and accumulated data to be studied at the end of the test.